1. Field of the Invention
The present invention relates to a solid electrolyte capacitor and a manufacturing method therefor more particularly to an organic semiconductor solid electrolyte capacitor using 7,7,8,8,-tetracyanoquinodimethane (hereinafter referred to as "TCNQ") complexes as an electrolyte.
2. Related Art
One of inventors of the present invention has proposed various organic semiconductor solid electrolyte capacitors using a TCNQ complex as an electrolyte. For example, in the U.S. Pat. No. 4,580,855, there is disclosed a solid electrolyte capacitor wherein a TCNQ complex of N-substituted isoquinoline of which the substituent at N atom is an alkyl group is used as an electrolyte. The solid electrolyte capacitors of this type exhibit excellent high frequency characteristics and, therefore, are widely used for switching power sources or the like.
In recent years, according to the necessity of miniaturization of electronic apparatuses, capacitors of this type are also demanded to miniaturize as chips which are mountable directly on a printed circuit board using reflow solder.
In general, the TCNQ complex is too weak to resist the heat applied upon soldering capacitor of chip type and deterioration of performance of the capacitor such as an extraordinary increase of the leakage current or the like is experienced. Accordingly, in order to improve the heat resistivity of the TCNQ complex, some TCNQ complexes having melting points higher than those of the conventional TCNQ complexes have been developed.
However, TCNQ complexes having been developed until now exhibit improved heat resistivities but the electrical conductivities of them are considerably lowered in comparison of that of the conventional isoquinoline TCNQ complex when solidified by cooling after melted once. Due to this, they have disadvantages in that the excellent high frequency characteristic which is the most important property of the capacitor using a conventional TCNQ complex is lost.